Transferring mechanism of the coating rod in friction surfacing
TL;DR: In this article, a coating rod of 1Cr18Ni9Ti (321) was deposited on the substrate of mild steel 1020 to perform a friction surfacing experiment, and the temperature changes of special points on the coating rod were measured using a thermocouple.
Abstract: A coating rod of 1Cr18Ni9Ti (321) was deposited on the substrate of mild steel 1020 to be able to perform a friction surfacing experiment. The temperature changes of special points on the coating rod were measured using a thermocouple. The results show that the temperature increase rate at the friction interface reached a high level at first. Then the rate decreased to a low level once the friction system became quasi-steady and the temperature became approximately stable near the melting point of the coating rod. The theory of contact melting was used to build the physical model for the quasi-liquid layer. Subsequently, the corresponding calculations were carried out. The computer simulation results are found to be consistent with the experiment results, and as such, the present study demonstrates the feasibility of applying contact melting theory to the study of friction surfacing. Likewise, this study reveals that the material at the top of the coating rod is plastic, and that it behaves as a quasi-liquid in the friction surfacing process. The study establishes the theory basis for the study of the mechanism of friction surfacing, and provides a new method for investigating other friction-welding techniques.
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TL;DR: Friction stir welding (FSW) has achieved remarkable success in the joining and processing of aluminium alloys and other softer structural alloys, however, it has not been entirely successful in the manufacturing of different desired materials essential to meet the sophisticated green globe requirements as discussed by the authors.
347 citations
TL;DR: Friction surfacing (FS) is a solid state technology with increasing applications in the context of localized surface engineering and has been investigated mainly for producing fine grained coatings, which exhibit superior wear and corrosion properties.
198 citations
Cites background from "Transferring mechanism of the coati..."
...Liu et al. (2008) presented a physical model based on the theory of contact melting to study the material transferring mechanism in the deposition of AISI 321 stainless steel on mild steel....
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...Physical model of coating rod in friction surfacing based on the quasi-liquid layer concept (Liu et al., 2008)....
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...Liu et al. (2008) stated that by the end of the initial deformation phase, the main heat source shifts from interfacial friction to plastic deformation....
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TL;DR: In this paper, sound multi-layered deposits in various ferrous materials were realized using friction surfacing in both single-and multi-track approaches, and samples with fully enclosed internal cavities were also successfully produced.
Abstract: In this work, we explore the possibility of utilizing friction surfacing, an emerging solid-state surface coating process, for layer-by-layer manufacture of three-dimensional metallic parts. One possibility in this regard (single-track friction surfacing) is to utilize friction surfacing for depositing a track or layer of material (sufficiently wide to cover the entire layer area), which is subsequently shaped to its corresponding slice counter using CNC machining. Another possibility (multi-track friction surfacing) is to generate a layer from multiple overlapping tracks of friction surfaced material, which is subsequently shaped as required using CNC machining. In the current work, sound multi-layered deposits in various ferrous materials were realized using friction surfacing in both single- and multi-track approaches. Samples with fully enclosed internal cavities and those consisting of different materials in different layers were also successfully produced. The deposits showed fine-grain wrought micr...
84 citations
Cites background from "Transferring mechanism of the coati..."
..., around 1200 C in the case of alloy 410) [15, 16, 19]....
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TL;DR: In this paper, the principle and process parameters involved in friction surfacing techniques, bonding mechanism, factors affecting the selection of process parameters, approach for the experimental work and testing of bond quality by various methods.
78 citations
TL;DR: In this article, a process parameter window was developed for satisfactory deposition of tool steel coatings, and the effects of process parameters on coating characteristics and integrity were evaluated, and it was shown that coating width is a strong function of mechtrode rotational speed, while coating thickness is mainly dependent on substrate traverse speed.
Abstract: Tool steel H13 was friction surfaced on low carbon steel substrates. Mechtrode (consumable rod) rotational speed and substrate traverse speed were varied, keeping the axial force constant. The effects of process parameters on coating characteristics and integrity were evaluated. A process parameter window was developed for satisfactory deposition of tool steel coatings. Coating microstructures were examined using optical microscopy, scanning electron microscopy, and transmission electron microscopy. Microhardness tests, shear tests, and bend tests were conducted on coatings. The results show that coating width is a strong function of mechtrode rotational speed, while coating thickness is mainly dependent on substrate traverse speed. Lower mechtrode rotational speeds results in wider coatings, while higher substrate traverse speeds produce thinner coatings. Thinner coatings exhibit higher bond strength than thicker coatings. Coatings show no carbide particles, yet exhibit excellent hardness (above 600 HV) in as-deposited condition due to their martensitic microstructure.
75 citations
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TL;DR: In this article, the temperature distribution and microstructural evolution of the friction stir welding of 6061 aluminum alloy (T6-temper condition) to copper are investigated. But the main focus of the work is on the microstructures of the weld.
372 citations
TL;DR: In this paper, microstructures in friction stir welds between monolithic AA2024 and AA2014 reinforced with 20 vol% particulate Al 2 O 3 have been analyzed and shown that the narrowest layers of each material are about 0.1 mm thick.
91 citations
TL;DR: In this paper, the authors describe the events that the matrix and carbides experience as the coating material pass from the coating rod to the substrate, in forming the coating, and the coating is observed to harden automatically within a few seconds of being deposited onto the cold substrate.
Abstract: This paper is concerned with the friction surfacing of high-speed steels, BM2, BT15 and ASP30 onto plain carbon steel plate. The events that the matrix and carbides experience as the coating material pass from the coating rod to the substrate, in forming the coating, is described. The coating is observed to harden automatically within a few seconds of being deposited onto the cold substrate. This autohardening is observed to be an inherent feature of the friction surfacing process and the only post-coating heat treatment required is tempering, as with traditionally hardened high-speed steels. The mechanism of autohardening is discussed in terms of the mechtrode/coating/substrate thermal system.
85 citations
TL;DR: Friction surfacing of tool steel, inconel, aluminum and titanium rods onto mild steel substrates and (ii) stainless steel, mild steel and inconel onto aluminum substrates was investigated in this paper.
71 citations
TL;DR: In this article, a neurofuzzy-model based decision support system, FricExpert, is proposed to speed up the parameter selection process and to assist in obtaining values for cost effective development.
59 citations